I have a theoretical scenario to propose for our new loan, just wondering if there's any considerations or structures worth looking in to, or if its a disaster waiting to happen. We're about to purchase a PPOR with a mortgage of approx $550k. Say I have a family member who has some spare cash which they are willing to park in our offset (the loan amount will be fully offset) with the intention that we split the difference between their potential high interest savings rate and our variable rate. Of course I've suggested they look at other investments, but they want to keep the cash very liquid so they are keen on looking into the viability of this arrangement. My intention would be to have 2 x offsets, one for their cash so that it remains completely untouched and another for our own savings. I'm assuming this would help manage the calculation of interest earned too. Are there any traps, taxation issues or problems you can see? I feel slightly uneasy about this, but can see there been benefit for both of us. Some potential issues I can think of: 1. I would be paying their portion of interest earned from my own cash flow 2. I could potentially miss the boat on fixing at a low interest rate, depending when they remove the cash.